Question 974015
Dimensions of Factory:  x and y.
Uniform Width of Lawn Around Factory:  w.
Total Area Combined:  (x+2w)(y+2w).
Area of Just Factory:  xy.
Description means,  (x+2w)(y+2w)=2xy.


Known Variables,
x=80
y=60
-
Unknown Variable,
w


Solve this for w.
{{{highlight_green((x+2w)(y+2w)=2xy)}}}.  It will be a quadratic equation.  Go as far as you can purely in symbols before substituting for x and y to evaluate w.